Grinding apparatus



Oct. 28, 1952 Filed April 5. 1949 E. STEPHANSEN 2,615,638

GRINDING APPARATUS 2 SHEETS-SHEET 2 1,, an. Er I" J'fe lun r Patented Oct. 28, 1952 GRINDING APPARATUS Erik Stephansen, Bestun, Oslo, Norway, assignor to Papirindustriens F Norway orskningsinstitutt, Oslo,

Application April 5, 1949, Serial No. 85,690

In NorwayDecember 17, 1946 The present invention relatesto a grinding apparatus for fibrous materials for instance cellulose, of the type which comprises two grinding elements one of which, the so called roll, has the shape of a body of rotation for instance a cylinder or a cone which conveniently is provided with knives along the circumference and is rotatably mounted on its axis. The other grinding element has the shape of a case, which encloses the roll and which is likewise rotatably mounted on its axis, the grinding being effected between the roll and the inner wall of the case co-operating with the roll.

The invention relates to .an embodiment of such an apparatus, which is particularly convenient for use in laboratories for performing grinding tests. For this purpose the apparatus comprises a vertically arranged spindle, two sleeves mounted on the spindle each of which sleeve carries two horizontalarms arranged in opposite directions, the arms of one of the sleeves at their oppositely directed ends carry respectively a bearing for a grinding roll mounted on a vertical axis, and a motor which serves to drive the said roll, whereas the arms on the other sleeve at their oppositely directed ends carry respectively a bearing for a rotatably mounted case adapted to enclose the said roll during the grinding operation, and a motor adapted to rotate the said case. At least one of the sleeves is conveniently rotatably mounted on the spindle in such a way that the roll and the case are reciprocally adjustable in radial direction. The apparatus comprises for thispurpose a device by means of which a determined grinding pressure can be maintained.

By this construction there is obtained a series of factors which influence the grinding operation that can be adjusted independently of each other such as, for instance, the speedof rotation of the case and the rollas well as the'relative speed of periphery of these two elements. Furthermore the pressure of grinding can-be adjusted and kept constant independently of the turning moments of the motors. Under the infiuence of the centrifugal force, the material takes the shape of an annular layer on the inside of the wall of the case, which layer rotates with the case. As a consequence of this forced rotation the apparatus can grind material of any consistence.

A feature of the apparatus according to the invention consists in that at least one of said sleeves is arranged in such a way that it can be lifted and lowered on the spindle. In this way 1 Claim. (01141-199) the roll and the casingmay easily be removed from each other axially. I

.In'the following the invention will be described more in detail in connection with the drawing, which illustrates an embodiment of an apparatus according to the invention. Figure.

l is a side view of agrinding apparatus according to the invention ready for use, partly in section. 1

Figure .2 Figure 1.

Figure 3 is a plan view corresponding with Figural. g

, I is a base plate carrying a vertical spindle 2. Close to the upp r, end of the spindle is rotatably mounted a sleeve.3.' This is provided with one laterally projecting horizontal arm 4 at the, left end of which is rotatably mounted an axle 5 parallel with the spindle. To the lower end of the axle is secured the grinding roll 6 which along its periphery is provided with teeth 1. 1

To the upper end of the axle 5 is secured a pulley 8.

The sleeve 3 is, in the opposite direction to the arm l, furthermoreprovided with an arm 9 whichcarries a motor [0.

The axleof the motor is arranged parallel with is a section on the line II-II in the spindle and is, atits upper end, provided with a pulley H which by means of a rope or a belt, I2 is drivingl connected with the pulley 8.

At adistance below the sleeve 3, on the spindle, there is .mounted another sleeve l3 which, by means of a, device to be described later, can be lifted and loweredonthe spindle but otherwise by means of a key 13a is prevented from turning on the spindle. The sleeve [3 is, like the sleeve,3,- provided with oppositely directed extending arms [4 and 23 of which the last mentioned carries a motor 24. At the left end of the arm [4 is rotatably. mounted a vertical axle [5, which at .its upper end is provided with a taperedheadlfi fitting into a tapered bore in a downwardly projecting hub I! on the under side of a casing of grinding l8, which in the working position of the apparatus encloses the roll 6. The shaft I5 and the head [6 can be firmly secured to the grinding case 3 and the hub IT by means of the nut I9. 20 is a cover for the case l8, which is open at the top. The cover is provided with a central opening 2| of diameter so that the axle can be moved laterally in the opening 2i.

At its lower end the shaft I5 is provided with a pulley 22.

As already mentioned the sleeve I3 is furthermore provided with an arm 23 extending oppositely to the arm I4 and which carries a motor 24. The vertically arranged axle of the motor is at its lower end provided with a pulley 25 which by means of a rope or a belt 26 is in driving connection with the pulley 22.

On its lower part the spindle 2 is provided with teeth 21. To the sleeve I3 is secured a casing 23 in which a cylindrical body 29 is rotatably mounted, which body is provided with teeth engaging the teeth 21. The body 29 is furthermore provided with a second set of teeth 39 which engages worm threads 3I on the shaft 32 which is likewise mounted in the casing 28 and crosses the body 29. The screw 3I can be rotated by means of a cranked handle or hand-wheel 33. The casing 28 respectively the sleeve I3 is at 34 provided with a slit through which a screw '35 is extending. This screw is at one end provided with a knob or a curled edge and when screwed down serves the purpose of clamping the casing 29 or the sleeve I3 to the spindle in adjusted position.

Besides the arms 4 and 9 the sleeve 3 is provided with a third arm 31 which, in the embodiment presented in the drawing, extends perpendicularly to the first mentioned arms. The arm 31 is at its free end provided with a downwardly extending nose 38 for co-operation with the upper end of an arm 39 which is rotatably mounted on a stud 40 secured to the spindle. The arm 39 has a prolonged approximately horizontally extending arm H which at its free end is arranged for being loaded with one or more loads 42. The arms 39 and H are furthermore provided with a downwardly projectingarm 43 which can cooperate with a cam 44 which by means of a handle 45 can be rotated on the stud 46.

The apparatus is used in the following way:

When a portion of material has to be fed into the grinding case, the case has to be lowered from the position shown in the drawing. Before the case can be lowered the grinding roll 6 has to be withdrawn from engagement with the case.

This is performed by turning the handle 45 and thereby the cam 44 about 90 towards the right. The cam 44 will thereby push the arm 43 and turn same as well as the arms 4| and 39 counterclockwise. The nose 38 is thereupon disengaged from the arm 39 and the sleeve 3 with the arms 4 and 9 can be turned clockwise as seen in Figure 3. This turning may be performed automatically by use of a spring. Now the screw 35 is slackened and thereupon the handle 33 is turned whereby the body 29 will be rotated by engagement between the worm threads 3| and the teeth 30. The teeth on the body 29, not shown in the drawing, which are in engagement with the teeth 21 will thereby bring about the lowering of the sleeve I3 and the members secured to same. The grinding case I9 is consequently lowered while the cover 20 will remain upon the grinding roll 6. If so desired the case may now by screwing out the nut I9 be separated from the axle I5, freed from ground material and fed with a fresh portion of a mass to be ground. Thereupon the case is again secured to the head I6 on' the axle I5 and is, by turning the handle 33 in opposite direction, lifted to the position shown in the drawing.

Now both motors III and 24 are started. The motors may either be constructed for fixed speeds of revolutions or be so constructed that the number of revolutions can be regulated. The construction is made in such a way that the grinding roll 6 and the case I8 rotate in the same direction but with diflerent speed of periphery. When the motors .have been started the handle 45 is turned back to the position shown in the drawing so that the sleeve 3 by the effect of the load 42 will be turned to the position shown in Figure 3. The teeth 1 of the grinding roll Ii will hereby be pressed against the inner side of the casing I8 with a fixed pressure which may be regulated desired by varying the load 42.

I claim:

Grinding apparatus of the kind described, comprising a vertical spindle, two horizontal arms turnablymounted relatively to each other on said spindle intermediate their ends, two motors, one carried by each one of said arms at one end thereof, a grinding roll rotatably mounted on one of said arms at the end opposite said motor carried by said arm, a case rotatably mounted on the second of said arms at the end opposite the motor carried by said arm and adapted to enclose said grinding roll during operation, beltand-pulley connections between each of said motors and said grinding roll and said case respectively, a third arm secured to said arm carrying said grinding roll and extending substantially perpendicular to said arm, a horizontally extending arm pivotally mounted on said spindle and having a projection thereon contactable with said third arm and weight means carried at the free end of said horizontally extending arm, said horizontally extending arm being adapted by coaction between said projection and said third arm due to said weight for adjusting grinding pressure between said grinding roll and said case by varyin said weight.

ERIK STEPHANSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 112,213 Brady Feb. 28, 1871 438,633 Marshall Oct. 21, 1890 1,358,354 Bellinger Nov. 9, 1920 1,369,209 Wright Feb. 22, 1921 1,631,422 Loken June 7, 1927 2,237,978 Wall Apr. 8, 1941 

